Detection of oxidative intermediates in biological samples

Abstract

Methods are provided for detecting oxidative intermediates in biological samples. These methods may be used to advantage to assess oxidative kidney injury and mitigation of kidney injury in response to drugs, diet and other therapies in patients with chronic kidney disease.

What is claimed is:  
     
         1 . A method for detecting oxidative kidney injury in an animal, comprising: 
 a) obtaining a biological sample from an animal suspected of having kidney disease; and    b) detecting oxidatively damaged proteins and lipids in said biological sample, the presence of said oxidatively damaged proteins and lipids being indicative of oxidative kidney injury in said animal.    
     
     
         2 . The method of  claim 1 , wherein said biological sample is urine.  
     
     
         3 . The method of  claim 1 , wherein said oxidatively damaged proteins and lipids are detected using HPLC.  
     
     
         4 . The method of  claim 1 , wherein said oxidatively damaged proteins are carbonylated.  
     
     
         5 . The method of  claim 1 , wherein said lipid is malondialdehyde.  
     
     
         6 . The method of  claim 1 , wherein said animal is a human.  
     
     
         7 . A method for detecting oxidative kidney injury in a patient suspected of having kidney disease, comprising: 
 a) obtaining a urine sample from said patient suspected of having kidney disease; and    b) detecting the presence, if any, of carbonylated proteins in said urine sample.    
     
     
         8 . The method of  claim 7 , wherein the carbonylated proteins are detected in urine using HPLC.  
     
     
         9 . A method for detecting oxidative kidney injury in a patient suspected of having kidney disease, comprising: 
 a) obtaining a urine sample from said patient suspected of having kidney disease; and    b) detecting the presence, if any, of malondialdehyde in said urine sample, the presence of malondialdehyde being indicative of oxidative kidney injury.    
     
     
         10 . The method of  claim 9 , wherein malondialdehyde is detected using HPLC.  
     
     
         11 . A method for assessing the efficacy of a therapeutic agent for treating oxidative kidney injury administered to a patient suspected of having kidney disease, comprising: 
 a) determining the levels of oxidatively damaged proteins and lipids in urine from said patient before treatment with said therapeutic agent;    b) administering said therapeutic agent to said patient;    C) determining the levels of oxidatively damaged proteins and lipids in urine from said patient during treatment with said therapeutic agents; and    d) determining the levels of oxidatively damaged proteins and lipids in urine from said patient after treatment with said therapeutic agents, a change, if any, in the levels of oxidatively damaged proteins and lipids during and after administration of said therapeutic agents being indicative of the efficacy of said therapeutic agents in treating oxidative kidney injury.    
     
     
         12 . The method of  claim 11 , wherein said therapeutic agents are selected from the group consisting of angiotensin converting enzyme inhibitors, angiotensin receptor blockers and losartan.  
     
     
         13 . A kit for diagnosing oxidative kidney injury in a patient suspected of having kidney disease, said kit comprising: 
 a) an instructional material;    b) a tube or vial for obtaining a sample of urine from said patient suspected of having kidney disease;    c) at least one antioxidant reagent;    d) thiobarbituric acid; and    e) phosphoric acid.    
     
     
         14 . The kit of  claim 13 , wherein said at least one antioxidant reagent is selected from the group consisting of butylated hydroxytoluene and dinitrophenyl hydrazine.